Rough idle on warm start up (20 minutes), 87 7MGTE

Bru · 07-29-2011, 01:47 AM

The issues I was having with rough idling on starting a hot engine after sitting 20 or 30 minutes have basically gone away. I was thinking of replacing the cam position sensor when I thought maybe the problem is in the harness side. I noticed that the wires that went to the cam position sensor were looped down under some of the others in the harness where they branch apart as they come out of the plastic tunnel heat shield. Now that wire comes straight out on top and over to the cam positioned sensor plug. I no longer have to wiggle any wires or push on the rubber gromet that goes into the cam position sensor. I also had the P and Q letters connected backwards on the EGR vacuum modulator because I took off the cap to look inside at the filter and put it on backwards. The decal on top misled me. Those letters are also embossed on the base which are always correct. I've had some good experience with products made by Lubro Molly such as: Jectron Fuel Injection Cleaner ($5 at NAPA),Ventil Sauber Valve Cleaner ($4 at NAPA). The MoS2 Anti-Friction Engine Treatment makes the oil look dirty but it does run slightly cooler and makes the engine rev freer. I put half a can in the engine and the other half in the manual transmission where I am using 10W-30 motor oil anyway and a half a can of Lubro Moly "oil saver" to stop seal leaks. Shifts are improved. They make a concentrate specifically for gearboxes and rear ends (not for LSD though).
I got a tank of bad premium? gas and I improved it significantly by using a bottle of Lucas octane booster ($9 at Advance Auto on sale). They claim 3 to 4 octane numbers or 30 to 40 points on a tankful. Some boostaholics mix it with good premium gas for an added cushion to forestall knocking that retards the spark timing.

07-29-2011, 01:47 AM	#7
Bru Bone Stock w Upgrades ;-) Join Date: Apr 2010 Location: Tampa Bay Posts: 202	The issues I was having with rough idling on starting a hot engine after sitting 20 or 30 minutes have basically gone away. I was thinking of replacing the cam position sensor when I thought maybe the problem is in the harness side. I noticed that the wires that went to the cam position sensor were looped down under some of the others in the harness where they branch apart as they come out of the plastic tunnel heat shield. Now that wire comes straight out on top and over to the cam positioned sensor plug. I no longer have to wiggle any wires or push on the rubber gromet that goes into the cam position sensor. I also had the P and Q letters connected backwards on the EGR vacuum modulator because I took off the cap to look inside at the filter and put it on backwards. The decal on top misled me. Those letters are also embossed on the base which are always correct. I've had some good experience with products made by Lubro Molly such as: Jectron Fuel Injection Cleaner ($5 at NAPA),Ventil Sauber Valve Cleaner ($4 at NAPA). The MoS2 Anti-Friction Engine Treatment makes the oil look dirty but it does run slightly cooler and makes the engine rev freer. I put half a can in the engine and the other half in the manual transmission where I am using 10W-30 motor oil anyway and a half a can of Lubro Moly "oil saver" to stop seal leaks. Shifts are improved. They make a concentrate specifically for gearboxes and rear ends (not for LSD though). I got a tank of bad premium? gas and I improved it significantly by using a bottle of Lucas octane booster ($9 at Advance Auto on sale). They claim 3 to 4 octane numbers or 30 to 40 points on a tankful. Some boostaholics mix it with good premium gas for an added cushion to forestall knocking that retards the spark timing. Last edited by Bru; 05-10-2012 at 11:35 PM.